SPRINGFIELD -- A 39-year-old Southampton man who operated an indoor marijuana growing operation inside an Easthampton apartment was sentenced in U.S. District Court Monday to three years probation, a $2,500 fine and forfeiture of $300,000.

Gregory Krzanowski pleaded guilty in October to possession of marijuana with intent to distribute and three counts of money laundering, according to a release issued by U.S. Attorney Carmen M. Ortiz.

Police arrested Krzanowski in August 2011 after they found 97 marijuana plants and four pounds of marijuana packaged for distribution during a search of a Florence Road apartment in Easthampton. Police also seized a firearm, identified in court documents Winchester .22 caliber rifle.

Approximately five pounds of packaged marijuana was seized from a Southampton home as well.

Police said the street value of the marijuana seized in Easthampton and Southampton was approximately $150,000.

The money laundering charge stems from three dates in 2009 in which Krzanowski made cash deposits of the proceeds from this marijuana business into a bank account registered to a legitimate business that he operated, according to the release.

Krzanowski faced a maximum penalty of 20 years in prison and a fine of $1 million or more, according to court documents. The minimum penalty, which he received, calls for the three years of supervised release, according to court documents.

The case was prosecuted by Assistant U.S. Attorney Alex J. Grant of Ortiz’s Springfield Branch Unit. Krzanowski was sentenced by U.S. District Court Judge Michael A. Ponsor.